SkyTrak 8042 Service Manual - Manual (Page 71)

3-33 6036, 6042, 8042, 10042, 10054
Boom
3. If there is no adjustment left on the extend chains,
tighten the retract chain locknut (5) at the front on
the underside of the outer boom.
4. Recheck chain tension. Refer to Section 3.7.5,
“Boom Chain Tension Check.”
5. Further chain adjustment can be achieved by
loosening all three chain locknuts and moving the
rear retract chain clevis (6) from the original
mounting hole in the anchor plate to the next hole.
This is only acceptable when boom chain sag cannot
be acquired and the chain elongation measurement
is still less than 12.36 in (313 mm). Follow the
instructions in Section 3.7.6, a. “Component/
Assembly Verification.”
6. Recheck chain tension. Refer to Section 3.7.5,
“Boom Chain Tension Check.”
a. Component/Assembly Verification
The third (7) to second (8) boom section separation
should be checked when assembling new boom sections
or chains, or when the rear retract chain clevis has been
moved forward on the anchor plate.
Measure the separation (9) between the third and second
boom section top plates. The distance should be at least
8.5 in (216 mm) and not greater than 11 in (279 mm) with
the boom fully retracted and the chains properly
tensioned. A distance of less than 8.5 in (216 mm) could
result in interference and cause damage to boom
components.
If the distance is less than 8.5 in (216 mm) or greater than
11 in (279 mm):
1. Verify that the retract chain clevis (6) is not mounted
in the last hole in the anchor plate.
2. Make sure that the chain system is properly
tensioned. Refer to Section 3.7.5, “Boom Chain
Tension Check.”
3. To increase the separation distance: Loosen the
retract chain locknut (5) on the bottom of the boom
one or two turns and tighten the two extend chain
locknuts equally the same number of turns. A
minimum of one full thread on the clevis must
protrude beyond the collar of the locknut.
4. To decrease the separation distance: Loosen the
extend chain locknuts at the rear of boom equally
one or two turns and tighten the retract chain locknut
(5) the same number of turns. A minimum of one full
thread on the clevis must protrude beyond the collar
of the locknut.
5. Install the rear boom cover.
6. If the third to second boom separation distance
cannot be achieved, contact your local JLG service
distributor.
OA0513
5
MA9451
6
OH1091
8
9
7